Way of the Wolf: Book 1: Vampire Earth by E. E. Knight
Louisiana, 2065. A lot has changed in the 43rd year of the Kurian Order. Possessed of an unnatural and legendary hunger, the bloodthirsty Reapers have come to Earth to establish a New Order built on the harvesting of enslaved human souls. They rule the planet. They thrive on the scent of fear. And if it is night, as sure as darkness, they will come.
On this pitiless world, the indomitable spirit of mankind still breathes in Lieutenant David Valentine. Brought into the special forces of The Wolves--an elite guerilla force sworn to win back Earth--this is Valentine's first command in the Kurian Zone. Driven by the losses of his past and the hope of a future, Valentine is in it to win. No matter how long it takes. No matter what doom of fate awaits him beyond his wildest nightmares.
"If The Red Badge of Courage had been written by H.P. Lovecraft."--Paul Witcover, author of Waking Beauty